The present invention relates to an ion separation device.
Ion mobility spectrometers or separators are well known. One particular known ion mobility separator is described with reference to FIG. 7 of U.S. Pat. No. 6,630,662 (Loboda). The known ion mobility separator comprises a segmented quadrupole rod set ion mobility separator. An axial DC voltage gradient is maintained along the length of the ion mobility separator and a counterflow of gas is provided.
One problem with the known arrangement is that the ion mobility separator is essentially equivalent to a conventional ion mobility separator having a longer drift length. Although the arrangement disclosed in US-6630662 enables a more compact ion mobility separator to be provided it does not offer any other improvement.
It is desired to provide an improved method of separating ions and separation device.